Serious bowing and twisting of lumber

[Shekhar Malvadkar]

I recently bought expensive figured wood boards of quilted maple and bubinga from ebay. Soon after they arrived I saw a major bow and twist in the woods. The seller says that 99% of woodworkers keep their wood at this humidity and that 40 - 50% humidity range that I have indoors in my house caused them to change form. Non of my other boards which are slightly thicker changed any form. These include wet pieces of lumber recently cut.
I would appreciate if someone can tell me if his statement about 10 % maintained humidity is accurate. I personally cannot imagine storing all my wood at that humidity level which I believe never naturally occur here in the south. If this guy is telling the truth, how do 99 % of woodworkers keep there wood at 10 % humidity?
Thanks in advance.
Shekhar.

[george wilson]

Your humidity level of 40 to 55% is just fine. There is something wrong with the wood. The Smithsonian Museum keeps its collections at 55%. Maybe the wood was too green,or maybe it was kiln dried too quickly,and got stresses in it.

[Brian Kent]

Shekhar,

The average max temperature in Death Valley, California in July is 115°.

It's 232 feet below sea level.

Less than 2" of rainfall per year.

The average humidity in July in Death Valley is 15%.

No, 10% is not typical anywhere I've ever heard of.

Brian

[Mike Cutler]

I store all of my wood, including the types you purchased, in an unheated, non climate controlled garage in New England. Wood will release some stress when cut, and sudden changes in humidity can cause wood movement, but I keep neither my house or my shop at an rH of 10%. I think the seller is referring to the moisture content of the wood.
To keep a house or shop at 10% rH and less would take some real forethought.

[John Keeton]

To keep a house or shop at 10% rH and less would take some real forethought.Not to mention just plain unhealthy!! Anything below 35% in a home is hard on furniture, your house and human bodies. Your sinuses would tell you very quickly that you need more moisture in the air:D and your furniture would show the effects of sustained low humidity in a very visible way.

[Gary Herrmann]

I've bought a couple pieces of figured wood on the bay. I always ask the moisture content and always check when it arrives. If the seller can't tell me or gives me some ridiculous answer, I don't buy. One guy told me all of his wood is at 4% MC. Or a 12/4 board that is completely dry after air drying 6 months. I figure if they're telling me stuff like that, either they honestly don't know - which is possible, or they're trying to pull something - so I pass.

[Ken Werner]

Rel. Humidity of 10% in a home is ridiculous. What has been said by others above is absolutely correct. Unfortunately, if the seller is this dishonest or ignorant, it seems unlikely you can get much satisfaction from him.

[Mark Roderick]

Hold on! As others have noted, I think this is just a matter of confusion in terminology.

At a humidity level of about 50% and an air temperature of about 70 F, most American hardwood species would have a moisture content of about 10%, give or take. It sounds as if that's what the seller was talking about.

To me, it sounds as if the guy just sold you wet wood, i.e., wood that was probably at a moisture content of something like 20%, As it dried, it bowed.

You can buy a moisture meter fairly inexpensively. You should test the wood when you receive it, to make sure it is really "dry" (meaning moisture content of about 10%.

By the way, this can happen at reputable lumber yards as well. I recently purchased some bloodwood that was supposed to be dry and it twisted into a knot when I brought it back to my shop (ignoring my own advice, I failed to test the moisture content at the yard, even though I had my moisture meter!).

The bottom line is that the guy should be willing to replace the wood. No use returning it to him, it sounds as if it wouldn't be usable for anybody.

[David Keller NC]

Shekhar - You don't specify what constitutes a "major bow and twist", nor do you say how thick the wood is. With highly figured wood, particularly quilted maple, you should expect dimensional changes when the wood's moved from one humidity environment to another.

If the wood's fairly thick - say 12/4 (twelve quaters of an inch, or about 3" thick), then you should expect a bow, twist or cup in quilted maple of as much as 1/4" per 6" of width, for a total of 1/2" out of flat for a 12" wide board. A lengthwise bow or twist of as much as 3-4" per 6 feet in length is totally normal. Some boards will move more than this, some less.

It isn't impossible to have gotten wet wood, but I'd expect the Bubinga to have been kiln-dried, as it's imported from Africa by big suppliers, and they generally dry it in a kiln before selling it to smaller distributors or individuals. Nevertheless, you should still expect highly figured bubinga to move somewhat when the relative humidity changes by more than 10-20%.

[Thomas Knapp]

10% doesn't sound right for RH but it does for the MC (moisture content) of the wood. Normally dried wood runs between 6% and 15% MC. Kilns in our area usually shoot for 8%. Air dried is usually a little higher usually around 12%. The company I worked for, before I retired, does a lot of cabinet and mill work installations. We would not install our work until the permanent heating and cooling system was up and running. Our superintendent would also take daily humidity readings. We did not install woodwork if the humidity levels were too high. Unfortunately I don't know the humidity range they were looking for. Lumber is always going to move a little in a new environment and figured lumber unusually moves more than straight grained lumber. Ideally wood is allowed to acclimate to it's new environment before it is worked and installed. It really sucks to see joints, that were tight when you made them, open up when the wood shrinks. If your lumber has excessive movement, from improper drying, that is another matter. I hope you work things out with your supplier.

[Jim Koepke]

This has been an interesting and informative post for me.

Not having a moisture meter and now living in a high humidity area has taught me a few things. This thread has made them more apparent.

It has often happened to me when buying wood from the borg that even though it is carefully selected for lack of cracks and twisting, by the time it gets home, some has cracked and some has warped.

Recently on a day trip across the border into Oregon, we checked out a few lumber yards. One we found with the lowest prices had the least heating and enclosed areas for their lumber. It was covered, in open areas. We took a chance on a lot of pine. It has been in my shop for over a month now and has had the least movement or cracking of any pine in my experience. I guess the reason is it was not kept in an overly dry environment and therefore, there was not much change. Recently have had a similar experience with a hardwood and exotics seller in Portland. They have wide open doors in their storage area. Though the pieces are considerably smaller, there seems to be no problems like have been experienced with similar pieces bought from a source that kept them in an environment controlled area.

So it seems it may come down to the wood being forced to conform instead of being allowed to come to rest.

jim

[Mark Roderick]

Ideally, you want to build furniture under the same temperature and humidity conditions where it will be used. I'm building some boxes now for friends in Norway. Norway is a lot less humid in the summer than New Jersey, probably in the winder as well, so I've tried to keep that in mind as I figure out how much the wood will shrink and swell with the seasons. If I go visit in a year and the boxes are all cracked, I'll know I screwed up.

[Matt Ranum]

Then there are those boards that will twist no matter how its kept. The internal stress built up in the grain depending on what shape the tree was in when harvested and how it was sawed makes a big difference. I have sawed logs plenty of times over the years and it seems no matter what you will end up with boards that twist. Most of the time when you rip the board it will straighten right out.

I even have some rough cut Walnut I bought from a guy that has so much stress it when I rip it it some will actually "Pop" and crack ahead of the blade. One time I was cross cutting a piece of 1x10 Walnut on my RAS and when I got halfway through it it pinched and literally locked itself to the blade. Had an awful time getting it free. Bent the crap out of a $70 blade.

[David Gendron]

I leave in the Yukon(Canada) where the climat is realy dry(how ever not as dry as Dead Valley) and in my shop, that is around 40% humidity, the is usualy around 8% and wile my outside stack is around 12% to 14% and when ever I bring wood in the shop, I have no problems with wood not behaving other than if the wood is green and not sticked!
So I think that e-bay seller is full of it!!
David

[Shekhar Malvadkar]

Thanks for all the information. The seller is reluctantly agreed to take back one set of board. His later e-mails made lesser sense but I guess this happens when buying wood. I am not sure if he will pay for return shipping. I may need to get a hold of a moisture meter to confirm the moisture reading. I am tempted to let people know of this ebay exotic wood lumber seller. Let us see how he finally concludes the transaction.
Thanks again everyone for sharing knowledge.
Shekhar.